1. Field of the Invention
The present invention relates to a fastening device, and particularly to a fastening device for mounting a thermal module onto a heat-generating component.
2. Description of Related Art
FIG. 5 illustrates a conventional thermal module 30. The thermal module 30 includes a die-casting member 31, a heat pipe 32, a fin assembly 33 and a strip-like spring member 34. The die-casting member 31 has a bottom surface contacting with a heat-generating component (not shown) mounted on a printed circuit board (not shown). The heat pipe 32 includes an evaporator section received in a channel 312 of the die-casting member 31, and a condenser section contacted with the fin assembly 33. The spring member 34 includes a middle portion, and two ends for being attached to the printed circuit board. When the ends of the spring member 34 are attached to the printed circuit board via screws (not shown) extending through mounting holes 342 defined in the spring member 34, through holes 341 of the spring member 34 engage with posts 311 of the die-casting member 31 and the spring member 34 urges the die-casting member 31 towards the printed circuit board to mount the thermal module 30 thereon, whereby the die-casting member 31 can have an intimate contact with the heat-generating component mounted on the printed circuit board.
However, the channel 312 is defined in a central portion of the die-casting member 31 and the heat pipe 32 is usually mounted in the channel 312 via soldering. When the heat pipe 312 is inserted into the channel 312, the solder spread on the channel 312 will be scraped off. As a result, the heat resistance between the heat pipe 32 and the die-casting member 31 is greatly increased. Furthermore, if the heat pipe 32 has a size larger than that of the channel 312 due to machining tolerance, it is difficult to insert the heat pipe 32 into the channel 312.
What is needed, therefore, is a thermal module with a lower heat resistance and a good universality of application.